Dear Thomas,
thank you for your answer. I have experienced that pssing by the trigger is functioning well.

The only thing wrong is that the loop has no effect on the data of the records. And I hoped that someone could check the statement syntaxwise. Maybe I am doing something wrong in my logic.

Is the use of the for select do loop correct as stated? Maybe I have to use an update or insert statement except?

Thanks again for any input.
Kind regards
Christian